1. Field of the Invention
This invention relates generally to system packaging apparatus and, more particularly, to an apparatus for coupling modular hardware to both the bus of a digital system and to industrial end devices.
2. Description of the Prior Art
Modular hardware is typically coupled to the bus of a digital system through the use of a wire wrap, a ribbon cable, or a printed circuit motherboard with identical edgecard or pin and socket connectors. This technique is used in virtually every minicomputer and microcomputer mainframe and offers the advantages of flexibility and serviceability.
The coupling of this same modular hardware to real, industrial end devices such as relays, thermocouples, etc., has been accomplished in several ways. First, an appropriate termination can be supplied on the modular device itself. Second, the field wiring can be made into a special cable terminating in an appropriate edgecard or pin and socket connector. Third, a suitable termination assembly can be coupled to each end device, which assembly is then coupled to the modular device by means of a special cable. Finally, a suitable termination assembly can be connected directly to the modular device by means of a single edgecard or pin and socket connector.
As the cost of microprocessors continues to decline it is becoming more important to implement cost effective packaging for industrial systems. All of the above described techniques suffer from cost performance problems and are relatively inflexible.